Method for recovering high-quality C9 tertiary carboxylic acid from rectification residual liquid in production of pivalic acid

The invention relates to the technical field of chemical recovery, and provides a method for recovering high-quality C9 tertiary carboxylic acid from rectification raffinate in production of pivalic acid, which comprises the following steps: S1, carrying out coarse distillation on the rectification raffinate in production of pivalic acid, and collecting coarse distillation raffinate; s2, mixing the crude distillation residual liquid with a toluene solution of tetramethylthiourea, carrying out rectification, and collecting a rectification liquid; and S3, distilling the rectification liquid, and filtering the distillation residual liquid to obtain the C9 tertiary carbonic acid. According to the technical scheme, the problems of environmental pollution, resource waste and high cost caused by lack of a treatment method for the rectification residual liquid generated in the production of pivalic acid in the related technology are solved. 本发明涉及化工回收技术领域，提出了从生产特戊酸精馏残液中回收高品质C9叔碳酸的方法，包括以下步骤：S1、将生产特戊酸精馏残液进行粗蒸后，收集粗蒸余液；S2